just curious.... i have a 92 formula 5.0 tbi and i'm converting it to a 383 stroker.so far i have the rotating assembly, and a TCI street fighter th400 trans on layaway. as for the rear end, i'm not sure what should go with. i know its been changed before to an older axle but i'm not sure what year its from but its definitly and older style axle. when i was replacing the calipers in the rear, i bought the ones that were made for my car, but when i went home they were different. the calipers that are on there have like a hammer style e-brake accuator.

anyway... i was wondering if this rear end would hold up to a 383 with a TH400...

 

Probably not for long. You have a very heavy duty transmission behind a strong engine and the weakest rear end that you can get. The next thing that you need to purchase is a stronger rear end. The Moser 12 bolt is my favorite, but there are also 9 inch Fords that are made to bolt in. I recommend the 12 bolt with an Eaton posi.

 

If you do get the 12-bolt make sure it has bolt in axels, not c-clip axels like stock. C-clips are junk and have no place in a high performance car, plus based on your combo you may be required to run c-clip eliminators if your car is fast enough. C-clip eliminators are also junk. They are a band aid fix that tend to leak on the street. The right solution is to lop the housing ends off and have ends welded on that accept botl in axels like a 9". Typically you can get a bolt-in 12 bolt already set up like this from the factory.

In either rear make sure they use a solid pinion spacer, not a crush sleeve. This is another junk part that has no place in a high performance car. This one stupid $0.99 part is responsible for more rear end failures than most people realize.

Either a 12 bolt or 9" will handle the power. Shop around for the best price with the options you want.

 

Personally, I'd say use what's on the car for now. Chances are you'll break all the teeth off the ring and pinon eventually but it all depends on how you drive it and what kind of traction it gets. I pushed a 10 bolt into the high 11's before finally swapping in a 9" because I installed a transbrake in the transmission.

To upgrade the diff, there isn't a whole lot of options. A factory 9 bolt if you can find one is a bit stronger than the 7.5" 10 bolt but not by much. The 9 bolts were only available in the third gens for a few years and performance parts need to come from Australia. Your only other choices are an aftermarket bolt in 9", 12 bolt or Dana 60. None of them are cheap. For a complete, ready to bolt in diff, expect to pay around $2500.

An inexpensive option is to buy the 9" housing package which comes with axles. You provide a center section with gears, posi etc and use your current brakes on it. The housing package is around $1000 but because it's not complete, it's not yet a direct bolt in until you provide the remaining parts required.

 

I made one pass of 12.95 with my stroker, TCI 3500 stall, and turbo 400. I was on my way home and there was a loud thud and started howling. I barely made it home. The next day I ordered a 9" with a strange nodular center section and a detroit locker with 4.11 gears. I bolted it in for $2500. Best money I ever spent.